Jump to content
SAU Community

Gtr Issue

MsR

By MsR,
in Engines & Forced Induction

 Share

Recommended Posts

MsR Community Regular

MsR

Posted
Posted

recently took my car to the tracks and noticed some issues which were not there when it was tuned about a year ago (not putting the blame on anyone here)

at idle, when you tap the throttle, it feels like the revs drop momentarily. Even when you rev the car in neutral, it feels like there is hesitation below the revs pick up. any idea what this is?

also at wide open throttle (WOT) the top of 3 gear is splattering. is this lack of spark? i have a big fuel system in the car and on the dyno it was fine, but im sure real life situations are different to dyno.

and last thing is at wakefield, as i come in fast to a corner and brake (turn 2, fish hook and last corner) the car doesn't rev or do anything! it drops to neautral for about 2-4seconds then picks back up again. I've tried to rev match and downshift but nothing worked! Car drives on the street fine but this is concerning me.

Is it a Tune? Spark? Fuel?

Link to comment
https://www.sau.com.au/forums/topic/443762-gtr-issue/
Share on other sites
portaz Mentor

portaz

Posted
Posted

Sounds like fuel surge on corners , but u have bit fuel system , changed filter in last year? I'd be checking fuel pressure and also all fuel related electrical connections , sputtering up top happened to me recently and was a boost leak I didn't know about , if all if above ok I'd look at earthing coils directly before looking at tune,but you could contact your tuner usually they are more than happy to hp if they are any good lol

Link to comment
https://www.sau.com.au/forums/topic/443762-gtr-issue/#findComment-7297521
Share on other sites
MrStabby Grand Master

MrStabby

Posted
Posted

Simplest thing to start with for the 3rd gear splatter is to pull the plugs and take a look. Change them anyway if they're old. Don't run a wider gap.

Also, tunes don't last forever because all the components that produce power wear/get dirty etc and don't behave exactly like they did when the tune was done.

Agree that fuel surge is the last issue. As soon as that happens head off the track and back to Goulburn to fill up again, or take spare fuel and save the trip. You'll find it starts at about the same fuel tank level each time.

Link to comment
https://www.sau.com.au/forums/topic/443762-gtr-issue/#findComment-7297613
Share on other sites
Badgaz Experienced

Badgaz

Posted
Posted

i'm gonna make some guesses here.... you need to do this

i did this on my wifes GTR that had a missfire when up it in third. the second part might be that your tuner may not have done your accelerator correction, or it could be your TPS. make sure your tps is reading the correct voltage at idle i think its 0.45v-0.55v at throttle closed position, the voltage should increase to somewhere between 3-5v at WOT. you don't need to do this with the car going but just the ignition turned on.

whats your ECU ? can you datalog?

Link to comment
https://www.sau.com.au/forums/topic/443762-gtr-issue/#findComment-7297706
Share on other sites
MsR Community Regular

MsR

Posted
  • Author
Posted

shall be cleaning the fuel filters out this coming week. plugs checked out ok and did a quick compression test as well and engine seems good. strange why it would be spluttering down the straight if it was surging as that is what i would expect from cornering

fuel system consists of a Weldon 2015A fuel pump, Earls billet fuel filters, -8 lines to the surge tank, -8 hose all the way up to the engine then splitting up to 2x -6 at the fuel rail

Link to comment
https://www.sau.com.au/forums/topic/443762-gtr-issue/#findComment-7298613
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share
Go to topic listing


  • Similar Content

  • Latest Posts

    • Duncan
      Mistakes were made, my R34 Story

      By Duncan · Posted

      100% the factory sender is tapered, that is how it seals (well, that and teflon paste or tape)
    • Kinkstaah
      Mistakes were made, my R34 Story

      By Kinkstaah · Posted

      Thanks folks - I've saved a few links and I'll have to think of potential cable/adapters/buying fittings. First step will be seeing if I can turn the curren abortion of a port into something usable, then get all BSPT'y on it. I did attempt to look at the OEM sender male end to see if it IS tapered because as mentioned you should be able to tell by looking at it... well, I don't know if I can. If I had to guess it looks like *maybe* 0.25 of a mm skinnier at the bottom of the thread compared to where the thread starts. So if it is tapered it's pretty slight - Or all the examples of BSPT vs BSPP are exaggerated for effect in their taper size.
    • Duncan
      Mistakes were made, my R34 Story

      By Duncan · Posted

      Have a look at that (shitty) pic I posted. You can see AN -4 braided line coming to a -4 to 1/8 BSPT adapter, into a 1/8 BSPT T piece. The Haltech pressure sender is screwed into the long arm of the sender and factory sender (pre your pic) into the T side. You can also see the cable tie holding the whole contraption in place. Is it better than mounting the sender direct to your engine fitting......yes because it removes that vibration as the engine revs out 50 times every lap and that factory sender is pretty big. Is it necessary for you......well I've got no idea, I just don't like something important failing twice so over-engineer it to the moon!
    • GTSBoy
      Mistakes were made, my R34 Story

      By GTSBoy · Posted

      Yup. You can get creative and make a sort of "bracket" with cable ties. Put 2 around the sender with a third passing underneath them strapped down against the sender. Then that third one is able to be passed through some hole at right angles to the orientation of the sender. Or some variation on the theme. Yes.... ummm, with caveats? I mean, the sender is BSP and you would likely have AN stuff on the hose, so yes, there would be the adapter you mention. But the block end will either be 1/8 NPT if that thread is still OK in there, or you can drill and tap it out to 1/4 BSP or NPT and use appropriate adapter there. As it stands, your mention of 1/8 BSPT male seems... wrong for the 1/8 NPT female it has to go into. The hose will be better, because even with the bush, the mass of the sender will be "hanging" off a hard threaded connection and will add some stress/strain to that. It might fail in the future. The hose eliminates almost all such risk - but adds in several more threaded connections to leak from! It really should be tapered, but it looks very long in that photo with no taper visible. If you have it in hand you should be able to see if it tapered or not. There technically is no possibility of a mechanical seal with a parallel male in a parallel female, so it is hard to believe that it is parallel male, but weirder things have happened. Maybe it's meant to seat on some surface when screwed in on the original installation? Anyway, at that thread size, parallel in parallel, with tape and goop, will seal just fine.
    • Kinkstaah
      Mistakes were made, my R34 Story

      By Kinkstaah · Posted

      How do you propose I cable tie this: To something securely? Is it really just a case of finding a couple of holes and ziptying it there so it never goes flying or starts dangling around, more or less? Then run a 1/8 BSP Female to [hose adapter of choice?/AN?] and then the opposing fitting at the bush-into-oil-block end? being the hose-into-realistically likely a 1/8 BSPT male) Is this going to provide any real benefit over using a stainless/steel 1/4 to 1/8 BSPT reducing bush? I am making the assumption the OEM sender is BSPT not BSPP/BSP
×
×
  • Create New...